Wash the lamb`s lettuce thoroughly, pluck it into bite-sized pieces and arrange on a plate. Cut the salmon fillet into strips with a sharp knife. Peel the orange and cut into wedges, removing the partitions. Collect the juice and add to the dressing.
For the dressing, mix the yogurt, horseradish, sunflower oil, pepper, salt and orange juice. Mix well. Finally, spread the dressing over the salad and arrange the salmon fillet and orange pieces on top.